Electronic Telegram No. 2573 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network APPARENT NOVA IN M31: M31N 2010-10e Kamil Hornoch, Astronomical Institute, Ondrejov, and P. Hornochova report their discovery of apparent nova in M31 on a co-added 1800-s R-band CCD frame taken on Oct. 31.727 UT with the 0.65-m telescope at Ondrejov. The new object, designated M31N 2010-10e, is well visible on the co-added frame as well as on single images used for the co-added frame, but it is not present on numerous archive images taken at Lelekovice and Ondrejov. The object is visible also on a pre-discovery Ondrejov R-band CCD frame taken on Oct. 30.703 UT. M31N 2010-10e is located at R.A. = 0h42m57s.74, Decl. = +41o08'12".1 (equinox 2000.0), which is 151" east and 476" south of the center of M31. Available R-band magnitudes (unless otherwise noted) for M31N 2010-10e, measured by Hornoch: 2010 Oct. 28.703 UT, [21.1 (K. Hornoch and M. Wolf, 0.65-m telescope at Ondrejov); 29.711, [21.4 (Hornoch, 0.65-m telescope at Ondrejov); 30.703, 19.1 +/- 0.15 (Hornoch and Hornochova, 0.65-m telescope at Ondrejov); 31.727, 18.1 +/- 0.1 (Hornoch and Hornochova); 31.927, 18.05 +/- 0.1 (Hornoch and Hornochova); Nov. 3.057, 19.2 +/- 0.15 (Hornoch); 3.083, [19.2 (Hornoch; I-band); 4.838, 19.8 +/- 0.2 (Hornoch and Wolf); 9.951, 20.8 +/- 0.3 (P. Kusnirak, 0.65-m telescope at Ondrejov); 13.729, [21.2 (Hornoch and Hornochova); 23.141, [22.4 (O. Pejcha, 2.4-m Hiltner telescope at MDM Observatory; Sloan r'). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 December 8 (CBET 2573) Daniel W. E. Green